Crystallization Behavior in Poly(ether Imide)/Poly(butylene Terephthalate) Blends using a Spectroscopic Method

Abstract

Crystallization behavior of poly(butylene terephthalate) in poly(ether imide)(PEI)/poly(butylene terephthalate)(PBT) blends was analyzed by FT-IR ATR spectroscopy. The crystalline characteristic IR peaks of PBT were investigated as a function of the annealing time. It was also found that C5O stretching peak of PEI/PBT blend shifted to lower wavenumber as the crystallization of PBT in PEI/PBT blends proceeded. The trend of C5O peak shift in PEI/PBT blends was in good agreement with the crystallinity change of PBT. Crystallization behavior of PBT in PEI/PBT blend strongly depended on the composition of PEI/PBT blends. In case of high PBT weight fraction (2/8, 4/6 composition), crystallization of PBT occurred without any phase separation. However, PBT crystallization proceeded mainly in the PBT rich-phase after the phase separation at low PBT weight fraction (6/4, 8/2 composition).